The invention described herein may be made, used and licensed by and for The United States for governmental purposes without paying me any royalty.
In one aspect this invention relates to tailgate structures useful with large trucks. In a further aspect, this invention relates to an improved ladder structure for use with large trucks to facilitate ingress and egress by personnel from the vehicle.
Military cargo vehicles are also used to carry troops. These cargo vehicles are made in a wide variety of sizes and configurations to meet various needs and because the military must operate off road over very rough terrain, the axles and cargo bed are usually a substantial distance from the ground This makes it impossible for a person to enter the vehicle from ground level without at least one assisting step.
Presently the most common assisting step at the rear of a military cargo vehicle is a bracket extending above the tailgate used as a combination handle and step when the tailgate is lowered, troops or personnel entering the vehicle can step onto the bracket and then onto the cargo bed. This configuration has problems. First the bracket/step is generally a substantial height from the ground when the tailgate is lowered. This makes it difficult for many persons, particularly shorter persons to use the step. Also, the second step from the bracket onto the cargo bed is substantial in most cases. These problems are compounded by the fact that troops are frequently required to enter carrying battle gear which may weigh 100 pounds or more. This additional weight is not evenly distributed on their body and negatively effects balance. The resulting bracket structure slows the passage of persons from the truck, increases the chances for an accident, and increases exposure to weapons fire under battlefield conditions.
It would be desirable to have a ladder structure associated with the existing vehicle tailgate structure to provide additional steps when the tailgate is lowered and which can be stored on the tailgate when the tailgate is in its upright position.
The present invention relates to a ladder structure, for use with a cargo truck having a raised cargo bed with a tailgate, to improve ingress and egress of people to the cargo bed. The ladder structure has a bracket rigidly mounted to the tailgate with a mounting stud bond one comer of the bracket for mounting the ladder structure. The bracket also has first and second retention bosses, the bosses being located on the bracket a predefined distance from the mounting stud. The bracket may also have an aperture formed in the center portion to provide a more defined step for use by persons when they use the ladder.
The ladder structure attached to the rectangular bracket, has a pair of spaced, parallel side rails, and a plurality of rungs attached to and disposed between the side rails. A bearing is formed on one end of the ladder near one of the side rails and the bearing journaled on the stud. This bearing rotatably attaches one end of the ladder to the rectangular bracket in a manner that allows rotation of the ladder through an arc of about 90 degrees.
A detent, adapted to engage the retention bosses, is mounted on the same end of the ladder as the bearing but near the side rail opposite the bearing. The detent engages the first slotted retention boss to hold the ladder in a storage position when the tailgate is up for vehicle movement. When the ladder is rotated to a vertical position, the second slotted retention boss is engaged by the detent to hold the ladder in the deployed position.
The ladder has a handle with first and second parallel arms joined by a curved connector. The first parallel arm of the handle is coaxially mounted within one of the side rails, the first arm being free to move longitudinally with respect to the ladder rail. The second arm of the handle has a curved extension on the end of the second arm opposite the curved connector, the curved extension being directed towards the first arm. The curved extension has a headed protrusion that engages a complementary slot formed in the first ladder side rail. The slot has an offset depression associated therewith, the depression adapted to hold the head of the protrusion when the handle is in an upright position.